Summary: Recent work in the laboratory has focused on prostate cancer aggressiveness. Genome-wide association studies (GWAS) have identified a number of common SNPs that are associated with prostate cancer risk in populations of European descent, although these SNPs explain only a small fraction of the heritable component. Replication and fine mapping studies of these SNPs have focused largely on Europeans. African Americans have been evaluated less frequently despite their higher risk of prostate cancer. We established a panel of 1,536 SNPs including 34 SNPs from European-based GWAS and 38 flanking SNPs. Using these SNPs we genotyped blood samples from 1,060 African American and 1087 European American men with prostate cancer from the NC-LA Prostate Cancer Project (PCaP). We found four GWAS replication SNPs and 7 flanking SNPs associated with prostate cancer aggressiveness.